TRANSFORMER PROTECTION USING MICROCONTROLLER

TRANSFORMER PROTECTION USING MICROCONTROLLER

In practice relay protection is not provided against open circuits because they are not harmful in themselves

Introduction

•It is very important to minimize the frequency & duration of unwanted outages.

•This is a high demand imposed on transformer protection.

Thus Transformer Protection becomes a challenging problem in power system

•Various relaying principles have been proposed and used to protect transformer against different types of faults.

•Relays that use the over current over flux and overheating principles protect the transformer against over load and externally applied conditions.

•Differential relays protect the transformer against internal faults.

•Normally 10% of equipment cost is for its protection,but it should be as minimum as possible.

•Thus effects of faults can be minimized by quickly isolating the faulty elements from the rest of the healthy system.

•In this project, microcontroller based protection system of transformer has been explained and designed.

Causes of Faults

•Faults are basically due to failure of insulation.The insulation may fail because of its own weakening, or it may fail due to overvoltage.the weakening of insulation may be due to one or more of the following factors:

•Aging

•Temperature

•Chemical pollution

•Foreign objects

•Rain, hail, snow

•Other causes

Main Components

•Following are the main components relating to this project.

(1)Transformer

(2)Microcontroller

(3)Electronic circuitry

(4)Rly

(5)C.T.

(6)Temperature sensors

(7)Cooling fans

Methodology

Since the terminals of a trasformer are physically close together, it is an ideal situation for application of differential protection.

As microcontrollers are:

•Cheaper

•Fast

•Reprogrammable

•High accurate

So, Differential Protection using microcontroller is employed in this project